(This is the third of four posts detailing the mods that I have made to my CharGriller Smoker Pro.)

This mod insulates both the cooking chamber and the SFB using welding blanket material. Almost every square inch of the smoker is covered. For the SFB, 700F RTV gasket material is used to affix the blanket material and (because I don't trust the gasket material to act as a strong adhesive) #6 self drilling screws with washers secure the larger pieces. For the cooker, 500F RTV is used.

The welding blanket material came from 3 3'x3' Tillman O-PAN black felt blankets. I purchased them here: http://store.cyberweld.com/panfelwelbla.html because the were not available locally (and if ordered at a higher price). Cyberweld offers free shipping and a broad range of welding products. I have no affiliation with them.

I initially assumed that I would only insulate the cooker. During test burns it became obvious that I was losing much more heat from the SFB than the cooker itself.

The Tillman O-PAN black felt blankets are soft and smooth even after exposure to high temperatures. The working temperature is 1800F (max 3000F).

The result is attractive (IMHO) and effective.

This insulation process increased my test burn time by about 6 hours -- from 5.5 hours to more than 11 hours.

The Grill Fully UpholsteredThe silvery points are the heads of the self drilling screws and washers.

One 3x3 blanket each was used for the SFB, the upper half and the lower half (3 3x3 blankets in total).

The process I followed was to locate a straight edge of the material and RTV it along an edge of the cooker or SFB. Then I followed that same edge with the screws to insure a solid mechanical bond.

I then folded the material back from the material it would cover and laid down a pattern of RTV in the large area exposed, and finally at the opposite edge.

Then I laid the material carefully on the fresh RTV and smoothed it from the secured edge to the new edge with a rounded object (one side of a 16' tape measure in my case). Once smooth from side to side I allowed the RTV to set for a few minutes and screwed down the new edge.

Finally, cut out any holes that should penetrate the insulation (chimney, bolt holes, thermometer holes, etc). An Exacto knife is just the thing.
At this point I trimmed around the edge with kitchen shears (it cuts easily). Then I screwed down any other edges.

Note: The bottom half of the barrel has the grease drain port. I cut a circle around both openings and removed the blanket there. Then, I built up a barrier of RTV at the edge of the insulation, forming a raised ring (from which the grease will drip.)

This is intended to prevent the grease from soaking into the insulation around the edge and creating a fire hazard as well as a nasty cleaning problem.

I repeated this process with each part (ends of the cooking chamber and the SFB), fitting scraps where required.

Where two edges meet at a corner, I came around at the end and squirted a bead of RTV between them and pinched them together to close the corners.

I performed the insulation in three stages (one blanket each). First I removed the SFB and insulated it. Then I removed the bottom and insulated it.

Since I had neglected to purchase a third blanket (assuming I would only do the upper and lower halves) I reassembled it at this point and did a test burn. The results were encouraging enough that I ordered the third blanket.

When it arrived, I insulated the top in-place on the cooker. If I had had all three blankets to start with, I would have done it disassembled, as with the other parts.

SFB Detail

On the SFB, I insulated all the parts externally exposed, including the door and the ash box. You can see the copper colored 700F RTV better in the picture than in real life (for which I am grateful).

The SFB surface can exceed 700F, so one cannot depend too much on the RTV.

One side benefit of this process is that the danger of burns, especially to children are much reduced. There are still hot spots that would hurt, but there are no large areas that could cause catastrophic burns. Holding your hand on the insulated surface of the SFB is unpleasant, like a three second fire test.

Care must be taken, both on the SFB and the lower half of the cooker to keep the mating area between them clear of the insulating material. The outline is pretty clear, but I found a little extra trimming necessary when putting it back together.

Detail Right Side Upper HalfEdited to add note about grease drain handling.

My god man, you've invented the Char-griller cozie. I have heard of people laying a welders blanket over cookers but never installing one like you did. I like the firebox job as well. It sure hides any rust that will form. This is really impressive work! Please post quaterly photos of how this is holding up and thanks for sharing this.

Very nice work!! To say that I'm impressed, is an under statement.
You may have answered this question, but how does does that welding material used as a blanket react to wetness/dampness caused by rain/snow in case it does get wet? Is it somewhat water-proof or water-resistant?

...You may have answered this question, but how does does that welding material used as a blanket react to wetness/dampness caused by rain/snow in case it does get wet? Is it somewhat water-proof or water-resistant?...

I don't have much experience with full soaking, but I experimented with a scrap so that I could respond to your question.

The material is a synthetic, so it tends to be colorfast (naturally black) and undamaged by exposure to water.

However, I have noticed that it seems a bit hydrophillic (tends to absorb water) because the top seems to relax a bit when the it has been raining for a long time, even under cover. It tightens back up when it dries or is heated.

The scrap I tested soaked up water eagerly when placed under a faucet, rather like felt (which is how the blankets are described.) I infer that it is 'wetted' by water (not repelled).

I have been cooking under a covered patio in this, the local rainy season. The wetting characteristics are such that rain (or snow) directly on the smoker would probably defeat the insulation effect rather quickly. An umbrella or other cover would seem to be required.

If you need to use it in wet weather and uncovered, some other material might provide both insulation and water resistance. It would be tricky to add a water-proof layer to the PAN-O material that would hold up during use, at least on the SFB where the surface temperature can exceed 900F.

If the blanket were left a bit longer could it then be wrapped around the sides, front and back, as a seal, to stop smoke from leaking out? Would using the RTV silicone ( that was shown effective with the fiberglass rope seal) then hold this material onto the lids metal? Of course, in addition, I'd still attach it as shown in this thread. Is the blanket thick enough to make a seal effective? If not, could the rope be put under it to thicken it to the appropriate width?